CVE-2026-86452 — MISP Unauthenticated Mail Endpoints Allow Unbounded Storage Consumption and Request Flooding
Affected versions of MISP permit unauthenticated or weakly constrained request paths to perform persistent work without adequate input bounds or rate limiting. The users/forgot password-reset endpoint accepted an attacker-controlled email value without first imposing a reasonable length bound or validating its format. That value was then used to create an audit log entry and queue a password-reset job, causing the supplied value to be persisted more than once per request. The commit explicitly states that an unbounded unauthenticated request field was stored twice per call with no throttle. The fix adds: - a maximum email input length of 1024 bytes; - email-format validation before persistent work; - a per-source pre-authentication request budget; - HTTP 429 responses when that budget is exceeded; - a 15-minute cooldown for API-access request emails; - POST-only handling and CSRF protection for the API-access request endpoint. The new flood filter is specifically intended to limit persistent storage costs from anonymous requests such as password resets, registrations, and failed REST authentication attempts. Version affected: ≤2.5.45
Who exploits it and how urgent it is
A 0–100 score combining confirmed exploitation, ransomware and APT use, public exploits, EPSS and severity.
How the score was calculated
- Technical severity (high)+6
- Automatable exploitation (SSVC)+3
The score orders the patch queue; it does not replace your asset context (internet exposure, criticality, compensating controls).
Triage
Is it exploited, how likely is exploitation, what does it touch, and how severe do the sources call it.
CISA SSVC assessment CISA
Three decision points CISA publishes for the CVEs it assesses (SSVC 2.0.3). A stakeholder decision, not a severity score.
Remediation
Fixes and mitigations documented by the sources — linked to the original advisory.
- Documented patch — github.com (NIST National Vulnerability Database)
First 24 hours
Ordered from the record’s own fields — exposure first, because you cannot patch what you have not found. A rule-generated starting point.
- Identify exposed assets running the affected vendor/product/version combinations (MISP MISP, Misp-project Misp).
- The attack is network-based and needs no privileges: restrict exposure (ACLs, VPN, WAF) until patched.
- Apply the fixed version or the patch documented under Remediation.
- Search available logs for exploit probes matching the vulnerability class (denial of service), errors and authentication anomalies.
Affected scope
Vendor, product and versions as the sources word them.
| Vendor | Product | Versions | Status | Source |
|---|---|---|---|---|
| MISP | MISP | ≤ 2.5.45 | Vulnerable | CVE Program (cve.org) e CISA ADP |
| Misp-project | Misp | ≤ 2.5.45 | Vulnerable | NIST National Vulnerability Database |
Attack characteristics
The CVSS vector, decoded. It describes the attack, not your exposure to it.
Every base score collected
Sources score independently and may disagree; each row says who scored it and under which version.
| Score | Version | Severity | Expl. | Impact | Scored by |
|---|---|---|---|---|---|
| 8.7 | CVSS 4.0 | High | — | — | 5a6e4751-2f3f-4070-9419-94fb35b644e8 via NIST National Vulnerability Database |
| 8.7 | CVSS 4.0 | High | — | — | CIRCL via CVE Program (cve.org) e CISA ADP |
| 7.5 | CVSS 3.1 | High | 3.9 | 3.6 | nvd@nist.gov via NIST National Vulnerability Database |
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H (score shown at the top: nvd@nist.gov) Weakness MITRE
Weakness class according to MITRE’s CWE catalog.
Detection
Read off the CVSS vector and the weakness class. Starting points, not tested rules.
- Prioritize edge telemetry for the network-reachable component (proxy, WAF, IDS/IPS).
- Track CPU/memory spikes and availability drops correlated with request patterns.
Timeline
What happened to this CVE, newest first.
- 2026
- Affected products added · misp/misp
- SSVC assessment updated
- Record published
- Fix documented
- CVSS changed · 7.5
- Source status changed · → Modified
- Record created in this database
- CVE published
Source activity
Repeated readings are counted rather than listed.
- 1× Official description updated · Oct 15, 2026 – Oct 15, 2026
References
1 on the record
Elsewhere on this site
Related CVEs (same products)
- Medium CVE-2026-107276 MISP Email OTP Race Condition Allows One-Time Password to Be Consumed by Multiple Concurrent Requests 8d
- Medium CVE-2026-107278 MISP Object Sync Drops Objects and Attributes When Description Is Empty 8d
- High CVE-2026-107180 MISP: Forced TOTP Enrolment Bypassed via Non-Browser Request Types on otp_required Instances 8d
- Medium CVE-2026-107175 MISP Correlation Engine Fails to Refresh When Event Distribution or Sharing Group Changes 8d
- Medium CVE-2026-106513 MISP: Site-Admin Can Repoint Redis Workers to Attacker-Controlled Server via UI/API Configuration Change 9d
- Medium CVE-2026-104914 MISP: Soft-Deleted Attributes from Other Organizations Exposed via Attribute Search and Paginated View 13d
Not in any source we poll
Listed rather than left blank: an empty field and an unmeasured one look identical on screen, and only one is a reason to look elsewhere.
- No FIRST EPSS score.
- No confirmed IOCs, IP addresses, domains, file hashes, or malware artifacts supplied.
- No organization-specific asset inventory, compensating-control status, or patch deployment evidence supplied.
- No exploit packet captures, log samples, or incident case IDs supplied.
Answered from this record
Text assembled only from the fields above — no additional claims.
What should defenders know first?
CVE-2026-86452 is "MISP Unauthenticated Mail Endpoints Allow Unbounded Storage Consumption and Request Flooding", rated High. It affects MISP (MISP); versions are in the scope table. It is not in CISA KEV, which does not rule out exploitation. CVSS 7.5 describes technical severity. First verify whether exposed or business-critical assets run the affected versions, apply vendor fixes or mitigations, and preserve logs for review.
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